[Cluster-devel] [PATCH] tunegfs2: Add some malloc error checking

[Andrew Price]

Static analysis found a possible null pointer dereference due to a
missing check in read_super. The malloc'd memory was also not being
freed on error conditions. This patch adds a check for a null pointer
and frees the allocated memory.

Signed-off-by: Andrew Price <anprice at redhat.com>
---
 gfs2/tune/super.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/gfs2/tune/super.c b/gfs2/tune/super.c
index 65e8d5b..49d87d6 100644
--- a/gfs2/tune/super.c
+++ b/gfs2/tune/super.c
@@ -94,14 +94,21 @@ int read_super(struct tunegfs2 *tfs)
 	int n;
        	tfs->sb_start = GFS2_SB_ADDR << GFS2_BASIC_BLOCK_SHIFT;
 	block = malloc(sizeof(char) * GFS2_DEFAULT_BSIZE);
+	if (!block) {
+		perror("read_super: malloc");
+		return EX_UNAVAILABLE;
+	}
 	n = pread(tfs->fd, block, GFS2_DEFAULT_BSIZE, tfs->sb_start);
 	if (n < 0) {
 		perror("read_super: pread");
+		free(block);
 		return EX_IOERR;
 	}
 	tfs->sb = block;
 	if (be32_to_cpu(tfs->sb->sb_header.mh_magic) != GFS2_MAGIC) {
 		fprintf(stderr, _("Not a GFS/GFS2 device\n"));
+		tfs->sb = NULL;
+		free(block);
 		return EX_IOERR;
 	}
 	/* Ensure that table and proto are NULL terminated */
-- 
1.7.6